/* =========================================================
   /assets/site.css — 共享外壳（reset / 变量 / 页头 / 页脚 / 基础组件）
   ========================================================= */

/* ---------- reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.65;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; }
button { font: inherit; color: inherit; background: none; border: 0; }
p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

/* ---------- 变量 ---------- */
:root {
  --sea: #0B2E4F;
  --ink: #101820;
  --paper: #F7F2E8;
  --coral: #FF6B4A;
  --coral-deep: #C8482F;
  --gold: #C8A45D;
  --celadon: #2E8B74;
  --mist: #DDE9F1;
  --slate: #5F6F7E;
  --white: #FFFFFF;

  --hair-line: rgba(11, 46, 79, 0.16);
  --hair-gold: rgba(200, 164, 93, 0.55);
  --hair-light: rgba(247, 242, 232, 0.18);

  --rail-w: 78px;
  --wrap: 1240px;
  --gutter: clamp(18px, 4vw, 48px);
  --step: clamp(34px, 5.5vw, 76px);

  --font-sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: "IBM Plex Mono", "SFMono-Regular", Consolas, "Liberation Mono", Menlo, "Noto Sans SC", monospace;
  --ease: cubic-bezier(0.2, 0.7, 0.3, 1);

  --rail-w-current: 0px;
}

/* 桌面端为固定品牌轨道让出横向空间 */
@media (min-width: 1024px) {
  :root { --rail-w-current: var(--rail-w); }
  body { padding-left: var(--rail-w-current); }
}

/* ---------- 无障碍 ---------- */
.skip-link {
  position: fixed;
  left: 8px;
  top: -80px;
  z-index: 200;
  display: inline-block;
  padding: 12px 20px;
  background: var(--ink);
  color: var(--paper);
  font-size: 14px;
  font-weight: 800;
  text-decoration: none;
  border-left: 4px solid var(--coral);
  transition: top 0.18s var(--ease);
}
.skip-link:focus { top: 8px; }

:focus-visible {
  outline: 2px solid var(--coral);
  outline-offset: 3px;
}

#main-content:focus-visible {
  outline: 2px dashed var(--coral);
  outline-offset: -6px;
}

/* ---------- 中文排版基准 ---------- */
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 0.55em;
  color: var(--sea);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.01em;
  text-wrap: balance;
}
h1 { font-size: clamp(2.25rem, 5.4vw, 3.75rem); line-height: 1.05; }
h2 { font-size: clamp(1.6rem, 3.4vw, 2.5rem); }
h3 { font-size: clamp(1.15rem, 1.9vw, 1.4rem); line-height: 1.3; }
h4 { font-size: clamp(1rem, 1.5vw, 1.12rem); line-height: 1.35; }

a { color: var(--sea); }

.lede {
  max-width: 60ch;
  margin: 0 0 1.2em;
  font-size: clamp(1.02rem, 1.4vw, 1.2rem);
  line-height: 1.75;
  color: var(--slate);
}

.mono {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--slate);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: var(--slate);
}
.eyebrow::before {
  content: "";
  width: 26px;
  height: 1px;
  background: var(--gold);
  flex: none;
}

.divider {
  height: 0;
  border: 0;
  border-top: 1px solid var(--hair-line);
  margin: 0;
}

.gridlines {
  background-image:
    linear-gradient(to right, rgba(11, 46, 79, 0.055) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(11, 46, 79, 0.055) 1px, transparent 1px);
  background-size: 32px 32px;
}

/* ---------- 布局容器 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: var(--step); }
.section--rule { border-top: 1px solid var(--hair-line); }

.section--mist { background: var(--mist); color: var(--ink); }

.section--band {
  background: var(--sea);
  color: var(--paper);
}
.section--band h1,
.section--band h2,
.section--band h3,
.section--band h4 { color: var(--paper); }
.section--band .lede { color: rgba(247, 242, 232, 0.78); }
.section--band .eyebrow { color: rgba(247, 242, 232, 0.7); }
.section--band .divider { border-top-color: var(--hair-light); }

.section--ink {
  background: var(--ink);
  color: var(--paper);
}
.section--ink h1,
.section--ink h2,
.section--ink h3,
.section--ink h4 { color: var(--paper); }
.section--ink .lede { color: rgba(247, 242, 232, 0.76); }

/* ---------- 网格 ---------- */
.grid {
  display: grid;
  gap: clamp(16px, 2.2vw, 28px);
  grid-template-columns: repeat(var(--cols, 12), minmax(0, 1fr));
}
.grid--2 { --cols: 2; }
.grid--3 { --cols: 3; }
.grid--4 { --cols: 4; }

@media (max-width: 960px) {
  .grid--3,
  .grid--4 { --cols: 2; }
  .grid--2 { --cols: 1; }
}
@media (max-width: 620px) {
  .grid { --cols: 1; }
}

/* ---------- 图片容器基础规则 ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  background: var(--mist);
  border: 1px solid rgba(11, 46, 79, 0.14);
}
.media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media--wide { aspect-ratio: 21 / 9; }
.media--square { aspect-ratio: 1 / 1; }
.media--tall { aspect-ratio: 3 / 4; }

.media--plot::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: linear-gradient(
    to top right,
    transparent calc(50% - 0.5px),
    var(--hair-gold) calc(50% - 0.5px),
    var(--hair-gold) calc(50% + 0.5px),
    transparent calc(50% + 0.5px)
  );
}

.media__caption {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--slate);
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 13px 22px;
  border: 1px solid var(--sea);
  border-radius: 0;
  background: var(--white);
  color: var(--sea);
  font-size: 15px;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: 0.01em;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.16s var(--ease), color 0.16s var(--ease),
              border-color 0.16s var(--ease), transform 0.16s var(--ease);
}
.btn:hover {
  background: var(--sea);
  border-color: var(--sea);
  color: var(--paper);
  transform: translateY(-2px);
}
.btn:active { transform: translateY(1px); }

.btn--primary {
  background: var(--coral);
  border-color: var(--coral);
  color: var(--ink);
}
.btn--primary:hover {
  background: var(--coral-deep);
  border-color: var(--coral-deep);
  color: var(--white);
}

.btn--ghost {
  background: transparent;
  border-color: var(--gold);
  color: var(--sea);
}
.btn--ghost:hover {
  background: var(--gold);
  border-color: var(--gold);
  color: var(--ink);
}

.btn--sm {
  padding: 9px 16px;
  font-size: 13.5px;
}

/* ---------- 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 13px 0;
  border-bottom: 1px solid var(--hair-line);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--slate);
}
.breadcrumb__link {
  color: var(--sea);
  text-decoration: none;
  border-bottom: 1px solid var(--gold);
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease);
}
.breadcrumb__link:hover {
  color: var(--coral-deep);
  border-bottom-color: var(--coral);
}
.breadcrumb__sep { color: var(--gold); }
.breadcrumb__current {
  color: var(--ink);
  font-weight: 700;
}

/* ---------- 卡片 / 标签 / 步骤 ---------- */
.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 28px);
  background: var(--white);
  border: 1px solid var(--hair-line);
  transition: border-color 0.18s var(--ease), transform 0.18s var(--ease);
}
.card:hover {
  border-color: var(--coral);
  transform: translateY(-3px);
}
.card__idx {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.card--mist {
  background: var(--mist);
  border-color: rgba(11, 46, 79, 0.12);
}
.card--ink {
  background: var(--sea);
  color: var(--paper);
  border-color: var(--hair-gold);
}
.card--ink h3,
.card--ink h4 { color: var(--paper); }
.card--ink .card__idx { color: var(--gold); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 11px;
  border: 1px solid var(--gold);
  border-radius: 999px;
  background: transparent;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--sea);
}
.tag--ok {
  border-color: var(--celadon);
  color: var(--celadon);
}

.steps {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--hair-line);
}
.steps__item {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: baseline;
  gap: 14px;
  padding: 14px 2px;
  border-bottom: 1px solid var(--hair-line);
}
.steps__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--gold);
}
.steps__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.6;
  color: inherit;
}

/* =========================================================
   页头
   ========================================================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: var(--paper);
}

/* ---- 左上坐标细条 ---- */
.coord-strip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 6px var(--gutter);
  background: var(--sea);
  color: rgba(247, 242, 232, 0.82);
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
}
.coord-strip__item {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.coord-strip__dot {
  flex: none;
  width: 5px;
  height: 5px;
  background: var(--coral);
  transform: rotate(45deg);
}
@media (max-width: 719px) {
  .coord-strip { display: none; }
}

/* ---- 主条 ---- */
.header-bar {
  position: relative;
  background: var(--paper);
  border-bottom: 1px solid var(--hair-line);
  box-shadow: 0 1px 0 rgba(11, 46, 79, 0.04);
}
.header-bar__inner {
  display: flex;
  align-items: center;
  gap: 12px;
  max-width: var(--wrap);
  margin-inline: auto;
  padding: 12px var(--gutter);
  min-height: 68px;
}

/* ---- 品牌 ---- */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--sea);
  flex: none;
}
.brand__glyph {
  position: relative;
  width: 36px;
  height: 36px;
  flex: none;
  background: var(--sea);
}
.brand__glyph::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--coral);
  clip-path: polygon(0 0, 100% 0, 0 100%);
}
.brand__glyph::after {
  content: "";
  position: absolute;
  inset: 5px;
  border: 1px solid rgba(247, 242, 232, 0.55);
}
.brand__text {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.brand__name {
  font-size: 17px;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: 0.02em;
  color: var(--sea);
}
.brand__sub {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  color: var(--slate);
  line-height: 1.3;
}
@media (max-width: 559px) {
  .brand__sub { display: none; }
}

/* ---- 导航 ---- */
.nav { margin-left: auto; }

.nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: nav-i;
}
.nav__item { display: block; }

.nav__link {
  position: relative;
  display: block;
  padding: 9px 11px 10px;
  border: 1px solid transparent;
  color: var(--sea);
  font-size: 14px;
  font-weight: 500;
  line-height: 1.2;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease),
              transform 0.16s var(--ease);
}
.nav__link::before {
  counter-increment: nav-i;
  content: "0" counter(nav-i);
  margin-right: 7px;
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: 0.06em;
  color: var(--gold);
  vertical-align: 2px;
}
.nav__link:hover {
  color: var(--coral-deep);
  border-color: var(--hair-gold);
  transform: translateY(-2px);
}
.nav__link[aria-current="page"] {
  color: var(--ink);
  font-weight: 800;
}
.nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 11px;
  right: 11px;
  bottom: 3px;
  height: 2px;
  background: var(--coral);
}

/* ---- 右侧动作区 ---- */
.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: none;
  margin-left: 6px;
}

.pill-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 18px;
  border: 1px solid var(--coral);
  border-radius: 999px;
  background: var(--coral);
  color: var(--ink);
  font-size: 14px;
  font-weight: 800;
  line-height: 1.2;
  text-decoration: none;
  white-space: nowrap;
  transition: background 0.16s var(--ease), color 0.16s var(--ease),
              border-color 0.16s var(--ease), transform 0.16s var(--ease);
}
.pill-cta::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--ink);
  opacity: 0.72;
  flex: none;
}
.pill-cta:hover {
  background: var(--coral-deep);
  border-color: var(--coral-deep);
  color: var(--white);
  transform: translateY(-2px);
}
.pill-cta:active { transform: translateY(1px); }

/* ---- 移动导航按钮 ---- */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 12px;
  border: 1px solid var(--sea);
  background: transparent;
  color: var(--sea);
  cursor: pointer;
  transition: border-color 0.16s var(--ease), color 0.16s var(--ease);
}
.nav-toggle:hover { border-color: var(--coral); color: var(--coral-deep); }
.nav-toggle__label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
}
.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: background 0.18s var(--ease);
}
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: transform 0.18s var(--ease);
}
.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after { top: 6px; }

.site-header[data-open] .nav-toggle { border-color: var(--coral); color: var(--coral-deep); }
.site-header[data-open] .nav-toggle__bars { background: transparent; }
.site-header[data-open] .nav-toggle__bars::before { transform: translateY(6px) rotate(45deg); }
.site-header[data-open] .nav-toggle__bars::after { transform: translateY(-6px) rotate(-45deg); }

/* ---- 移动端抽屉 ---- */
@media (max-width: 1023px) {
  .nav-toggle { display: inline-flex; }

  .nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    margin-left: 0;
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    background: var(--sea);
    border-top: 1px solid var(--hair-gold);
    border-bottom: 1px solid var(--hair-gold);
    transition: max-height 0.28s var(--ease), visibility 0.28s var(--ease);
  }
  .site-header[data-open] .nav {
    max-height: 72vh;
    overflow-y: auto;
    visibility: visible;
  }

  .nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 6px 0;
  }
  .nav__item { border-bottom: 1px solid var(--hair-light); }
  .nav__item:last-child { border-bottom: 0; }

  .nav__link {
    padding: 15px var(--gutter);
    border: 0;
    color: var(--paper);
    font-size: 16.5px;
    font-weight: 600;
  }
  .nav__link::before { color: var(--gold); font-size: 10.5px; }
  .nav__link:hover {
    transform: none;
    color: var(--coral);
    border-color: transparent;
    background: rgba(247, 242, 232, 0.06);
  }
  .nav__link[aria-current="page"] {
    color: var(--white);
    background: rgba(255, 107, 74, 0.16);
    box-shadow: inset 3px 0 0 var(--coral);
  }
  .nav__link[aria-current="page"]::after { display: none; }
}

@media (max-width: 400px) {
  .pill-cta { padding: 8px 13px; font-size: 13px; }
  .nav-toggle { padding: 8px 10px; }
  .nav-toggle__label { display: none; }
}

/* ---- 左侧固定品牌轨道（桌面端） ---- */
.rail { display: none; }

@media (min-width: 1024px) {
  .rail {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 70;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-between;
    width: var(--rail-w);
    padding: 18px 0 16px;
    background: var(--sea);
    color: var(--paper);
    border-right: 1px solid var(--hair-gold);
  }
  .rail__glyph {
    width: 14px;
    height: 14px;
    flex: none;
    background: var(--coral);
    clip-path: polygon(0 0, 100% 0, 0 100%);
    box-shadow: 0 0 0 1px rgba(247, 242, 232, 0.35);
  }
  .rail__word {
    writing-mode: vertical-rl;
    text-orientation: mixed;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.34em;
    color: rgba(247, 242, 232, 0.92);
    margin: 14px 0;
  }
  .rail__track {
    position: relative;
    flex: 1 1 auto;
    width: 2px;
    min-height: 80px;
    background: rgba(247, 242, 232, 0.2);
    overflow: hidden;
  }
  .rail__fill {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 0;
    background: var(--coral);
  }
  .rail__coord {
    margin-top: 12px;
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.1em;
    color: var(--gold);
  }
}

/* =========================================================
   页脚
   ========================================================= */
.site-footer {
  position: relative;
  background: var(--ink);
  color: var(--paper);
}
.site-footer::before {
  content: "";
  display: block;
  height: 10px;
  background: linear-gradient(90deg, var(--coral) 0 58%, var(--gold) 58% 100%);
  clip-path: polygon(0 0, 100% 0, 100% 52%, 0 100%);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.45fr;
  gap: clamp(24px, 3vw, 42px);
  max-width: var(--wrap);
  margin-inline: auto;
  padding: clamp(40px, 6vw, 64px) var(--gutter) 34px;
}

.footer-brand__mark {
  position: relative;
  display: block;
  width: 34px;
  height: 34px;
  margin-bottom: 16px;
  background: var(--sea);
}
.footer-brand__mark::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--coral);
  clip-path: polygon(100% 0, 100% 100%, 0 100%);
}
.footer-brand__mark::after {
  content: "";
  position: absolute;
  inset: 6px;
  border: 1px solid rgba(200, 164, 93, 0.7);
}

.footer-brand__name {
  margin: 0 0 6px;
  font-size: 18px;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--paper);
}
.footer-brand__line {
  margin: 0;
  max-width: 24ch;
  font-size: 13.5px;
  line-height: 1.7;
  color: rgba(247, 242, 232, 0.62);
}

.footer-col__title {
  margin: 0 0 14px;
  padding-top: 12px;
  border-top: 1px solid var(--hair-gold);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--gold);
}

.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
}
.footer-link {
  display: inline-block;
  padding: 5px 0;
  border-bottom: 1px solid transparent;
  color: rgba(247, 242, 232, 0.86);
  font-size: 14.5px;
  text-decoration: none;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease),
              transform 0.16s var(--ease);
}
.footer-link:hover {
  color: var(--coral);
  border-bottom-color: var(--coral);
  transform: translateX(3px);
}

.footer-contact__line {
  margin: 0 0 8px;
  font-size: 14px;
  line-height: 1.6;
  color: rgba(247, 242, 232, 0.86);
  word-break: break-word;
}
.footer-contact__line--mono {
  font-family: var(--font-mono);
  font-size: 13.5px;
  letter-spacing: 0.02em;
  color: rgba(247, 242, 232, 0.94);
}
.footer-contact__note {
  margin: 14px 0 0;
  font-size: 12.5px;
  line-height: 1.7;
  color: rgba(247, 242, 232, 0.52);
}

.footer-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
  max-width: var(--wrap);
  margin-inline: auto;
  padding: 16px var(--gutter) 26px;
  border-top: 1px solid rgba(247, 242, 232, 0.14);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: rgba(247, 242, 232, 0.58);
}
.footer-bar__legal,
.footer-bar__note { margin: 0; }

@media (max-width: 980px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-col--contact { grid-column: 1 / -1; }
}
@media (max-width: 560px) {
  .footer-grid { grid-template-columns: 1fr; gap: 26px; }
  .footer-col--contact { grid-column: auto; }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .nav__link:hover,
  .footer-link:hover,
  .btn:hover,
  .pill-cta:hover,
  .card:hover { transform: none; }
}